Yellowstone reports few bison deaths this winter
By Cory Hatch, Jackson Hole, Wyo.
March 27, 2009
After a year when hunting, management actions and a harsh winter wiped out nearly 50 percent of Yellowstone’s bison herd, officials say the park’s iconic species has fared well so far this winter.
Biologists, using a combination of aerial surveys and ground-based observations in February, estimated the herd has about 2,900 animals. That’s down from an estimated population of about 3,000 last summer.
Hunters killed only one animal during a bison hunt in Montana this year, and the park has not taken any animals to slaughter for leaving the park boundary to date, Yellowstone National Park spokesman Al Nash said. Biologists estimate about 100 animals succumbed to winter conditions in the park.
“Circumstances are different than they were last year,” Nash said. “I think, in part, we’ve had a different winter. While we certainly had significant snowpack in the interior, our snowfall in the northern part of the park appears to have been lighter than last year. It’s easier [for bison] to get at food.”
Nash said good precipitation last winter and last summer also helped the bison population by providing an abundance of forage.
The relatively mild winter and good forage likely kept animals from migrating outside the park boundary, which triggers federal and Montana wildlife managers to start capture and slaughter operations because of fears the bison will spread the disease brucellosis.
Nash said Yellowstone’s central herd had been wintering in the Pelican Creek area of Hayden Valley but has recently begun to move west. The animals are still within the park boundary.
“That is not to say that we might not see some movement between now and spring green-up, which would typically be in the next three weeks or so,” Nash said.
If animals do move out of the park’s West Entrance, they still could be protected. Officials recently signed an agreement that would allow limited numbers of bison to winter on the Horse Butte Peninsula in West Yellowstone, Mont.
By this time last year, state and federal wildlife managers had captured and shipped to slaughter 1,087 animals, hunters had killed 166 animals, and 74 calves were removed from the population for a quarantine feasibility study. By year’s end, 1,435 animals were shipped to slaughter, 166 were killed in the hunt and 112 were removed for the study.
In total, a population that numbered 4,700 in the summer of 2007 dwindled to about 2,500 by spring 2008.
Stephany Seay, media coordinator for the Buffalo Field Campaign, questioned Yellowstone’s numbers for this year.
“Their population estimate is politically driven,” she said. “They inflate it for management [purposes].”
